Monogamy relations for relativistically causal correlations

Understand

Non-signalling conditions encode minimal requirements that any (quantum) systems must satisfy in order to be consistent with special relativity.

• Recent works have argued that in scenarios involving more that two parties, correlations compatible with relativistic causality do not have to satisfy all possible non-signalling conditions but only a subset of them.
• Here we show that correlations satisfying only this subset of constraints have to satisfy highly non-local monogamy relations between the effects of space-like separated random variables.
• These monogamy relations take the form of entropic inequalities between the various systems and we give a general method to derive them.